1. Field of the Invention
The present invention relates to a graphics display terminal's capability to provide a fill-pattern inside a redrawn panel outline to produce a redrawn panel image, the redrawn panel outline being generated on a display subsequent to generation of an original panel image having said fill pattern present therein.
2. Description of the Prior Art
Some of the graphics display terminals of the prior art possessed a panel-fill capability, wherein a fill-pattern was designated and a closed-boundary image, or panel, was drawn on the display of the terminal, the fill-pattern filling the space inside the panel. However, these graphics display terminals of the prior art did not possess a zoom capability, wherein a portion of the displayed panel image is magnified in order that the fine details of the displayed panel image may be studied and/or modified as desired. With the advent of the zoom capability for graphics display terminals, the user could, for example, zoom in on a portion of a displayed panel image including the fill-pattern filling the space inside the panel. When this zoom operation is performed on the displayed panel image, the displayed panel image is erased, and it is redrawn on the screen as a redrawn panel image. The zoom capability of the terminal redraws the zoomed outline of the panel image on the terminal display, resulting in a magnified panel outline. The panel fill capability of the terminal should determine which area, on both sides of the magnified panel outline, represents the area inside the panel outline, and which area represents the area outside the panel outline. However, the panel fill capability of the prior art graphics display terminals could not determine which area, on both sides of a magnified panel outline, represented the area inside the panel, and which area represented the area outside the panel. Consequently, since it was not known which area represented the area inside the panel, it was not possible to fill the zoomed panel outline with the predesignated fill pattern.
In addition, the graphics display terminals of the prior art did not possess a capability whereby a multiple number of viewports could be displayed on the terminal display, portions of the originally displayed panel image being displayed inside each of the viewports. The portions of the originally displayed image were sometimes subjected to a zoom operation, the zoomed portions of the originally displayed panel image being displayed in their corresponding viewports. However, again, with the advent of the ability to display these multiple viewports, if the multiple viewport capability was used in conjunction with a filled panel representing the originally displayed image, the terminal was capable of redrawing the outline of the panel in the viewport, but, in the case of an expanded panel outline, the terminal's original panel-fill feature was not capable of determining which area represented the area inside the panel, and which area represented the area outside the panel.